Reform won five seats at Colchester City Council and eight at Southend-on-Sea City Council, but once again, both councils remain under no overall control.
Labour lost three seats to Reform in the coastal city
Southend council leader Daniel Cowan said there had been “no talk of local services” during the campaign.
“That really concerns me,” Cowan said.
“People have been elected on a national message, but nobody knows what their local mandate is. These elections are about local services, not national politics.”
Reform did not replicate its gains in Harlow, where the Tories won all 11 seats on the district council that were up for election – increasing their majority.
It has been a mixed picture for the Lib Dems in the county.
At Brentwood Borough Council, they won enough seats to remain the largest party, but it remains under no overall control.
Colchester’s leader, Lib Dem David King, said it reflected “national discontent with established parties”.
The Greens managed to retain their seats on Essex County Council, and made two gains at Southend – but otherwise have not had huge breakthroughs so far in Essex.